1. Technical Field
This disclosure relates to systems that convert electric energy into mechanical energy or vice versa and, more particularly to an arrangement of coils and/or magnets that covert electric current into mechanical power or vice versa.
2. Related Art
Some motors and generators generate many current components and fluxes including certain third harmonic currents and fluxes (e.g., the alternating cycle is three times the fundamentals). Under certain conditions such as when the power density of an electric machine is very high, the magnetic saturation in the electric machine may become very high. A third-harmonic flux within the air gap of the machine may be a by product of this saturation.
Unfortunately, in some electric machines third harmonic currents render zero-sequence currents that do not generate torque. Zero-sequence third-harmonic ampere-turns in a three phase machine, for example, may buck each other in the air gap. The counter balance of such forces may produce no torque since torque is produced by the stator ampere-turns interacting with the rotor flux.